Biosafety evaluations of plant research require the assessment and analysis of the plants alone as well as of the biological organisms associated with the plants, either naturally or introduced in planned experiments. Hence, the term “plant” refers to both the plant and its associated biological organisms. Plant research discussed in this chapter is conducted in specialized facilities that allow for plant growth and manipulation, collectively referred to here as containment facilities. Such facilities may be greenhouses, growth chambers, and modified laboratories that serve as places for growing plants under controlled conditions. Some of these facilities are specialized to isolate plants from biotic risks in the environment or to control fluctuations in abiotic or environmental factors. Although a particular plant can exist in an environment with wide variability in ambient temperature, light, nutrition, and other essential growth components, environmental conditions must be controlled to ensure scientific reproducibility. It is generally accepted that reducing variability, in this case by controlling environmental conditions, results in better scientific predictability. Furthermore, these actions enable other researchers to reproduce the experiments.